Hey all, I finished building my 2.4GHz circuit board for controlling Power Functions motors and servos with a hobby RC transmitter. It turned out as well as I hoped, giving full proportial speed control, all 7 servo positions on either side of 0 degrees, and the servo snaps back to center, just like you would expect it to when you let go of the steering wheel. You can drive two motors, or two servos, or one of each.
It fits in a 4x6 stud area, 3 bricks tall. If I used a shorter voltage regulator I could have gotten it down to 2 bricks tall, so not much bigger than the IR receiver.
I posted my bill of materials, the PCB etching art, and the microcontroller program on my blog so that anybody with basic electronics skills can build their own. There's also pictures of the process and a video of the final product. Here's the link:
http://brianzawesome...ions-radio.html
I have wanted to have radio controlled LEGO cars since I was a little kid, and now I can. I have also wanted to document a project on the internet for a while too, so I'm pretty pumped on both counts.
Brian Z